Marine anchor alarm



Feb. 18, 1969 w. P. ISAACSON MARINE ANCHOR ALARM Filed May 6, 1966 M/ALTER F? /5AAC50A/ FIG.

United States Patent 8 Claims This application is a continuation-in-part of allowed application Ser. No. 345,610 filed Feb. 18, 1964, now abandoned.

The invention herein disclosed pertains to means for promoting safety of a marine vessel at anchor, and more particularly, to means for providing a signal or alarm incident to dragging of an anchor relative to the bottom with which it is engaged.

As is well understood by those skilled in the marine arts, a vessel at anchor is subject to the vagaries of movements of the water and the atmosphere. As a consequence, a constant watch is maintained on vessels of any appreciable size, whereby timely warning may be given of adverse change of conditions so that proper action may be taken. In the case of many vessels, especially small vessels, maintenance of a continuous watch during periods of open anchorage is uneconomical or impractical. In such cases, need for an automatically-acting means capable of initiating or producing an alarm or signal is evident. The present invention provides means for producing a signal incident to dragging of an anchor; and when embodied in its most complete physical form the invention provides means for producing a sense-perceptible signal or alarm at a selected location on the vessel, or, alternatively, at a location distant from the vessel.

Briefly stated, the invention comprehends movement sensing means located at the anchor and effective to generate or produce a signal when the anchor is dragged or drawn through the material of the sea bottom. The sensing means or sensor may be in the form of a movable device secured to the anchor and capable of continuing movement under force applied thereto by bottom material moving therepast incident to dragging of the anchor; the movement of the device relative to the fluke, for example, of the anchor being utilized to generate or produce the signal. As herein explained and illustrated in only exemplary form, the sensor device comprises a rotary screw or propeller means rotatably disposed in an aperture in a fluke of the anchor, it being understood that the rotary means or rotor may be of other form such as a paddle wheel and so disposed or mounted as to be rotated as it moves across the bottom substance or as the latter is forced through the aperture incident to dragging of the anchor. The signal is created by signal means incident to rotation of the rotor, and may be a sound signal produced by a battery or gravity actuated soundemitting device, or may be an electric signal produced by permanent-magnet means carried by or forming part of the rotor and moved past activatable means afiixed to or mounted in the material of the anchor and supplied with suitable power. In the illustrated exemplary physical embodiments of the invention the activatable means comprises in one case a gravity-operated gong or resonator device and in another case comprises a magnetic reed switch that is incorporated in an electric signal circuit connected to a source of electric power, the signal circuit being connected to or comprising alarm means or, alternatively, comprising means to initiate corrective action. In the electric signal system as illustrated, the switch is disposed and arranged to be moved to the closed condition each time a rotor-carried magnet approaches the switch,

3,428,942 Patented Feb. 18, 1969 "ice the several components being so proportioned and constructed that the switch opens as the magnet recedes or moves away from the switch. The rotor may have several blades or vanes or threads, and the set of magnet means may be one or more magnets. For example, there may be one magnet for each blade, or only a single magnet in a selected part of the rotor. In the illustrative sonic signal version of the system, the rotor is used to elevate a hammer which is thereafter released to fall by gravitational action and strikes a bell-like gong or resonator to create a sound signal which is received by a transducer such as a hydrophone for initiating an alarm.

The preceding brief description of the invention makes it evident that it is a principal object of the invention to provide means for automatically producing a signal indicative of dragging of a marine anchor on the bottom of a body of water.

Another object of the invention is to provide means for providing an alarm incident to dragging of the anchor of a marine vessel.

Other objects and advantages of the invention will hereinafter be set forth in the appended claims or made evident in the following description of preferred physical embodiments as illustrated in the drawings forming part of this disclosure and in which drawings:

FIGURE 1 is a partly schematic diagram illustrating the general arrangement of principal components of an acoustic alarm system according to the invention, as the latter is applied to an anchored marine vessel;

FIGURE 2 is a functional diagram in schematic form, illustrating the functional disposition of principal units of the alarm system according to the inventoin illustrated in FIGURE 1;

FIGURE 3 is a fragmentary pictorial view, depicting to an enlarged scale, means disposed at the anchor of the system shown in FIGURE 1, and including a passageforming stator and a rotor supported therein within an aperture in a fluke of the anchor;

FIGURE 4 is a fragmentary section View, depicting details of the structures and parts shown in FIGURE 3;

FIGURE 5 is a schematic electrical block diagram illustrating the electrical relationship of components such as a hydrophone, amplifier, and alarm device which are located at the marine vessel or other station remote from the anchor;

FIGURE 6 is a schematic diagram depicting the electrical arrangement of components of a complete exemplary system embodying the principles of the invention using direct electrical signaling between anchor and vessel;

FIGURE 7 is a pictorial view of an exemplary marine anchor incorporating a movement sensor and indicating means according to the direct electrical signaling mode of the invention;

FIGURE 8 is a fragmentary View, partially sectional, showing a portion of a fluke of the anchor of FIGURE 7, in section with the electrical signal generating movement sensor in place in an aperture in the fluke, with the split-stator of the sensor shown in section and a tapered rotary screw device or rotor of the sensor in place in the stator, and with a portion of the rotor broken away and showing a detail, and with a portion of the stator broken away and showing the location of a reed switch;

FIGURE 9 is a pictorial view of the rotor or screw device of the movement sensor depicted in FIGURES 7 and 8;

FIGURE 10 is a sectional view of structure depicted in FIGURE 8, the view being taken on a plane and in the direction indicated by line 1010 of FIGURE 8; and

FIGURE 11 is an end view of the movement sensor de- 0 picted in FIGURE 8, viewed in the direction of arrow A in the latter figure.

The several figures or drawings are drawn to respectively different scales, in the interest of clarity and conciseness of illustration.

Referring first to FIGURE 1, there is depicted (in part only) a marine vessel V having an anchor engaged on the marine bottom B below the surface S of a body of water, the vessel V being connected or tethered to the shank 12 of anchor 10 by means of an anchor line 16 such as a chain or rope. Flukes 13 and 14 of the anchor are adapted in known manner to have limited movement relative to the shank and engage the bottom B and become more or less firmly hooked therein. The anchors may have an eye 12a for attachment of the chain or rope. Thus the latter element can apply dragging force to the anchor and may draw the anchor through or over the bottom when and if the vessel drifts appreciably.

In the illustrated exemplary embodiment of the invention, a passage is provided either by part of the anchor or by means connected to the anchor, the passage being so disposed that bottom material, such as mud, is forced by or through the passage if the anchor is dragged along the marine bottom beneath a body of water. As illustrated in FIGURES 3 and 4, the preferred form of passage is of somewhat tubular configuration and is provided by means 18 in the form of a stator that is secured to a fluke of the anchor, such as fluke 14, at a large aperture drilled or otherwise provided through the fluke as indicated. As is indicated in FIGURES l and 7, the anchor flukes of the exemplary anchor are of heavy sheet-metal; and as shown in FIGURE 4 fluke is provided with a set of one or more small holes or apertures such as 14b, radially spaced from and around aperture 14a and arranged to receive means such as bolts 20 for attachment of the passage-forming means to the anchor.

Referring particularly to FIGURES 3 and 4, stator 18 is formed with a peripheral flange 18 provided with holes 18h arranged complementary to the apertures 14b, for accommodation of bolts 20 which serve to secure the stator to fluke 14. The stator 18 further comprises a cylindrical portion or rim 18k dimensioned to fit in aperture 14a of fluke 14 of the anchor as indicated in FIGURE 4. Further the stator comprises a plurality of inwardly-extending struts such as 18s connected at their outer ends to rim 18k and integral at their inner ends with a hub 18m. Hub 18m1 is arranged to receive and support a stud 18q at the center of cylindrical rim 18k and coaxial therewith. Preferably stud 18g is threaded and received in the threaded bore of hub 18m and locked thereto by lock-Washer and nut means as indicated in FIGURE 4.

Rotatably supported on stud 18q between hub 18m and the head 18q' of the stud are a rotor 22 and a hammer 26, with bearing washers disposed between, as indicated in FIGURE 4. Rotor 22 is fitted with resonator elements 24, 24, which are disposed on the rotor so as to restrict rotation of hammer 26 to somewhat less than 180, for example, 150. The resonator elements, which are thin plate-like members embedded in and secured to the rotor, are such as to be struck by the hammer incident to rotation of the rotor, and to emit an acoustic or sonic signal when thus struck. Thus elements 24 may be made of strong bell metal, and may be of curved shape to enhance resonance. The rotor is adapted to be turned by bottom material (sand, clay or the like) upon the anchor being dragged; and to that end is provided with a series of angularly disposed blades 22!) (FIGURE 3) similar to or like marine propeller blades. For clarity of illustration, all but one of blades 22!) have been omitted from FIGURE 4.

Thus with the signal transmitting means comprising stator 18 and rotor 22 afiixed in place in the fluke 14 of the anchor, dragging of the latter along the bottom forces bottom material past blades 22b, thus causing the rotor to rotate. As the rotor rotates, hammer 26 is carried upwardly by one or another of elements 24, 24 and permitted to fall (rotating at the time about stud 18g) and strike the other of the resonator elements.

The acoustic signal, or signals, thus produced by impact of hammer 26 on one or both of resonator elements 24 are transmitted in all directions, but importantly along a signaling path indicated at 30 between the dragging anchor and the vessel V. At the latter, either affixed to the hull below the water line, or, preferably, suspended overboard on a line 30a as indicated in FIGURE 1, in a sensitive hydrophone or like acoustic detector device H. Thus irrespective of the heading of the vessel relative to the anchor, the acoustic detector or receiver transducer is situated for reception of the signal emitted by the signaling transmitter at the anchor. The hydrophone serves to transduce or translate the acoustic signals received into corresponding electric signals, as is well understood in the arts of sound and physics, and the electric signals are transmitted via the line 30a (which comprises insulated electrical conductors) to signal receiver and alarm means aboard vessel V.

Referring now to FIGURE 2, the functional arrangement of components of the alarm or system which are at the vessel is shown in block-diagram form. The receiving transducer illustrated by the first block comprises the hydrophone H. That component is connected :by conductors to an adjustable band-pass electronic amplifier unit 36, of conventional design and which serves to electronically amplify the signal output of the hydrophone H and to filter out undesired signals. The thus restricted output of the amplifier unit 36 is transmitted to an alarm unit 34, which may be simply a relay-controlled batteryoperated buzzer or electric bell, the relay being connected to be energized by the output signal of the amplifier unit and connected to cause energization and operation of the battery-powered buzzer or bell (or, alternatively, a blinker light or like conventional visible alarm) when energized. The details of the hydrophone, amplifier unit, and alarm signal unit 34 are not set forth since those units are, individually, commercially marketed components and are not per se the invention. The electrical operation of the vessel borne components may be understood by reference to FIGURE 5, wherein it is made clear that the output signal of the hydrophone is passed to the narrow-band amplifier 36, the output of. 36 passing to. a detector-power amplifier unit 36' such as a relay, whose output is connected to efiect switching of the power (such as that of a battery) to the blinker or aural alarm unit 34.

A variation of component organization according to the principles of the invention is depicted in FIGURES 6 through 11, wherein components similar to those of FIG- URES 1 through 5 bear numerals one hundred higher than those applied in the latter figures. As is indicated in FIGURE 6, the anchor comprises a pair of flukes 113 and 114, a shank 112 terminated by an eye 112a, and a stock 115. The anchor is attached to a rope or the like 116 which is secured in known manner to a vessel such as that depicted at V in FIGURE 1. Thus the vessel when moving provides a force which through the rope 116 may drag the anchor through or across the marine bottom. The fluke 114 is provided with a large aperture 114a in which a stator 118 (FIGURE 8) is secured, as by bolts such as 120 passing through additional apertures such as 11421 spaced around the principal aperture 114a. Stator 118 is, for reasons presently made evident, preferably composed of separable sections. Thus the stator comprises base section 1181) and a cap section 118c both formed as indicated in FIGURE 8 and so the two sections are secured together by the same bolts (such as bolt 120) as serve to secure the stator to fluke 114. While bolt 120 is depicted as passing through holes in the two stator sections, the stator sections, or either, may have properly disposed slots in lieu of bolt holes.

Rotatably disposed in the passage 118p provided by the stator 118 is a rotor 122 (FIGURE 9) that is formed or provided with means effective to cause rotation of the rotor when bottom material passes by the rotor. As illustrated and as preferred, the noted means is in the form of one or more helical vanes or ribs 122t in the form of threads or the like which give the rotor the form and nature of a screw. As depicted the rotor comprises four such threads, and the threads are, conveniently and preferably, formed integrally with an axially-extending body portion or core 122b. The rotor is provided with surfaces arranged and formed to slide on complementary bearing surfaces provided on the stator, whereby the rotor is rotatably supported by and confined against escape by the stator. As depicted, the ends of the rotor ribs are beveled, as at 122v and 122w, respectively, to be complementary to respective annular conical bearing surfaces 118v and 118w formed on the interior end faces of the stator sections 11817 and 1180 as indicated. The rotor 122 is formed with diametrical dimensions such as to provide slight clearance with the interior wall of the stator, to permit easy rotation of the rotor. The disposition of the stator relative to the face of the fluke of the anchor may be varied from that shown, depending upon the disposition of the fluke to the shank 112 of the anchor in any particular application, and is such as to cause bottom material to be forced into passage 118p or 11821 in a direction parallel to the double-ended arrow A in FIGURE 8 when the anchor is drawn along the bottom. In either event, the bottom material causes rotation of the rotor in the stator.

To provide signals or indications of the rotation of rotor 122 in stator 118, a set of one or more permanent magnets such as that denoted by numeral 124 is secured to the rotor to rotate therewith in one or more substantially circular paths that are closely adjacent to respective sensor means such as that illustrated in the form of a magnetic reed switch 126 that is afiixed by adhesive insulative resin or the like in a recess 118r formed in the interior of the stator sections 1181) and 1180 (FIGURES 8 and The arrangement is such that as a magnet 124 is moved past switch 126, the latter is first closed and then permitted to open as the magnet recedes. The switch 126, depicted diagrammatically in FIGURE 6, has one of its poles or terminals connected to a conductor 129, as indicated. Alternatively, as is indicated in FIGURE 6 by dotted lines, the conductor 128 may be grounded, or insulated and grouped with insulated conductor 129 and connected to signal means in the vessel or elsewhere. As indicated in FIGURE 7, the conductor means 130, forming a signal path and comprising insulated conductor 129, are brought out of-recess 118r through the resin, and, preferably in an armored sheath, are secured to a face of the anchor fluke alternatively by being embedded in a groove formed therein or by being secured thereto by conventional clips, and the conductor means are coursed to shank 112 with sufiicient slack at the juncture of the fluke, stock and shank to facilitate harmless bending. In those anchors wherein the shank is tubular, as is indicated in FIGURE 7, the conductor means are coursed into the interior of the the shank through an aperture adjacent the stock, and through the shank and out through an aperture adjacent the eye of the shank, and the apertures may be sealed with resin. Alternatively, if the shank is not hollow, the conductor means are enclosed in an armored sheath and clipped to the shank or secured thereto by adhesive, or both.

Above the eye of the anchor, the conductor means 130 are threaded through the anchor chain or are at intervals secured to the anchor cable or rope, as indicated in FIGURE 7, and are brought out to terminals 132 of signal apparatus 134 (FIGURE 6). The conductor means will ordinarily be somewhat longer than the anchor rope or cable, for evident reasons.

The signal means 134 may be dispersed or enclosed in a suitable container, depending upon circumstances in each application of the invention. The signal means comprises an alarm device 140 represented in FIGURE 6 as an electric bell, a source of power, 142, represented by an electric battery, and appropriate connections. As depicted in this exemplary apparatus, alarm device is an electric bell having a gong 140g, an armature 140a with a gong clapper, and an electromagnet 140m. The bell is connected between terminals 132 in series with the power source 142; and a holding resistor 144 is connected across the armature contacts of the bell, as indicated, using suitable conductors.

From the preceding description it is evident that in the absence of dragging of the anchor, switch 126 will remain either closed or open. Rotor 122 will be rotated incident to dragging of the anchor, however, and each time a magnet 124 is moved in the circular path past switch 126, the latter will be closed. Closure of switch 126 results in energization of the bell magnet, which draws the armature 140a and causes the clapper to strike the gong, and concurrently opens the armature contacts. The electromagnet remains energized, however, through current flowing through resistor 144, until reed switch 126 opens incident to continued rotation of rotor 122. Thus the bell sounds but once for each passage of a magnet into and away from proximity to switch 126; and hence the repetition rate of the sounding of the bell provides an indication of the rate of dragging of the anchor.

It will be evident from the preceding description that the alarm means depicted in FIGURE 6 may be used as signal means 34, except that terminals 132 would in that case be connected to the switch contacts of a relay energized by amplifier 36. Also the preceding description makes evident the full attainment of the stated objectives of the invention. In the light of the disclosure it is evident that variations and modifications within the true spirit and scope of the invention will occur to others skilled in the art, and accordingly it is not desired to limit the definition of the invention to the details of the illustrated preferred exemplary device except as it may be restricted by the appended claims.

I claim: 1. Means for sensing and indicating dragging of a marine anchor past bottom material at the bottom of a body of water, comprising:

first means, including a marine anchor, and means for applying force to the anchor in a direction tending to effect dragging of the anchor, said first means including means providing a walled passage through which bottom material is forced incident to dragging of the anchor through bottom material;

second means, including rotary means disposed in and retained in said passage by said first means, said rotary means being arranged to be rotated by passage of bottom material through said passage; and

third means, includig means for detecting and providing an indication of rotation of said rotary means relative to said first means, whereby dragging of the marine anchor past the bottom material at the bottom of a body of water is sensed and indicated incident to passage of bottom material through said passage.

2. Means according to claim 1, in which said first means includes a passage-forming stator secured at an opening through the said anchor, and wherein said rotary means includes a rotary screw device rotatable in said passage and held captive therein by said stator.

3. Means according to claim 2, in which said detecting means includes a magnetic-field responsive device in said stator and a magnetic-field producing device connected to and rotatable with said rotary screw device into and out of proximity to said magnetic-field responsive device.

4. Means according to claim 3, in which said magneticfield responsive device is a magnetic reed switch arranged to close and open incident to approach toward and retreat away therefrom, respectively, by said magneticfield producing device.

5. Means for sensing and indicating dragging of a marine anchor along the bottom of a body of water, said means comprising:

first means, including a marine anchor and means for causing dragging of said anchor past bottom material at the bottom of the body of water; second means, including rotary means connected to said anchor to travel therewith and rotatable relative to said anchor incident to contact with and movement relative to said bottom material; and

third means, including means for detecting and indicating rotation of said rotary means relative to said first means.

'6. Means according to claim 5, said first means including means forming a double-ended Walled passage through which bottom material is forced incident to dragging of the anchor, and said rotary means including a rotary screw device disposed in said passage to be rotated relative to said first means by travel of bottom material passing through said passage, and said third means comprising magnet means mounted on said screw device to rotate therewith in a path and comprising a magnetic reed switch carried by said first means in close proximity to the said path, whereby said switch is opened and closed incident to rotation of said screw device in said passage to provide an electrical indication of dragging of the said anchor.

7. Apparatus for indicating dragging of a marine anchor at the bottom of a body of water, comprising, in combination with the anchor and means to cause dragging of the anchor:

first means, including sensor means connected to the anchor for travel therewith and for sensing relative motion between material at the said bottom and the anchor, and

second means, including signal means for producing and transmitting indications of said sensor means of such relative motion to a location remote from the anchor.

8. Apparatus according to claim 7, in which said first means comprises signaling means at said anchor for cre ating sound-wave signals in the body of water incident to sensing by said sensor means of relative motion between material at the said bottom and the anchor, and in which said second means comprises a hydrophone situated in the water at the location remote from the anchor, and further includes means connected to the hydrophone effective to provide an alarm signal incident to reception by the hydrophone of a sound-wave signal created by said signaling means.

References Cited UNITED STATES PATENTS 2,810,120 10/ 1957 Parker 34029 3,217,291 11/1965 King 340-29 3,281,781 10/1966 Milton 34029 JOHN W. CALDWELL, Primary Examiner.

A. W. WARING, Assistant Examiner.

U.S. Cl. X.R. 

1. MEANS FOR SENSING AND INDICATING DRAGGING OF A MARINE ANCHOR PAST BOTTOM MATERIAL AT THE BOTTOM OF A BODY OF WATER, COMPRISING: FIRST MEANS, INCLUDING A MARINE ANCHOR, AND MEANS FOR APPLYING FORCE TO THE ANCHOR IN A DIRECTION TENDING TO EFFECT DRAGGING OF THE ANCHOR, SAID FIRST MEANS INCLUDING MEANS PROVIDING A WALLED PASSAGE THROUGH WHICH BOTTOM MATERIAL IS FORCED INCIDENT TO DRAGGING OF THE ANCHOR THROUGH BOTTOM MATERIAL; SECOND MEANS, INCLUDING ROTARY MEANS DISPOSED IN AND RETAINED IN SAID PASSAGE BY SAID FIRST MEANS, SAID ROTARY MEANS BEING ARRANGED TO BE ROTATED BY PASSAGE OF BOTTOM MATERIAL THROUGH SAID PASSAGE; AND THIRD MEANS, INCLUDING MEANS FOR DETECTING AND PROVIDING AN INDICATION OF ROTATION OF SAID ROTARY MEANS RELATIVE TO SAID FIRST MEANS, WHEREBY MATERIAL AT THE BOTTOM OF A BODY OF WATER IS SENSED AND INDICATED INCIDENT TO PASSAGE OF BOTTOM MATERIAL THROUGH SAID PASSAGE. 